Sprandom——一种用于大容量固态硬盘的快速伪随机预处理方法此外还更新了其与 FIO 集成的进展.pdf

1、Steven SprouseDeterministic,Fast,Random Preconditioning Using Sprandom in FIODeterministic,Fast,Random Preconditioning Using“Sprandom”in FIOSteven SprouseSTORAGETime spent testing is more valuable than time spent preparing the testPrevious time constraints were convenient,but:As SSD capacities incre

2、ase beyond 16TB,the time to randomly precondition these drives has also increased from several hours to several days.Brute force used to work,but:Traditional methods involve at least one sequential write followed by multiple random writes to reach a steady state.A single sequential write on a 128TB

3、drive can take 10 hours.Logically fill the drive:Every LBA shall be written once.Achieved by at least one logical drive writeReach a steady state throughput:Achieved through several random drive writes.Overprovisioning is distributed within the drive in a particular way.The Mechanics of Pre-Conditio

4、ning SSDsThe figure to the right shows roughly how the OP is distributed across the physical media in an SSD when a random write workload reaches steady state.In this example,there is 15%OP in the drive.What is the ideal“Pre-Conditioned”State?Goal:Combine the Fill and Steady State in a single pass.L

5、ogical Drive fills were taking too long,and required more time as capacities increased.Could we shape writes in a way that will still write every LBA at least once,while forcing the drive to go into garbage collection saving time on subsequent sequential or random writes?Steady state throughput is m

6、easurable,so we can compare methodologiesTest apples to apples after traditional and SPRandom pre-conditioning to ensure steady state operationReport and measure overprovisioning use and compare between methodologiesSanDisk Pseudo-Random Fast Preconditioning(SPRandom)Preconditioning redistributes ov